Prebiotics, such as oligosaccharides, are non-digestible dietary compounds broken down by the micro-organisms of the intestinal flora. The breakdown of prebiotics often exerts beneficial effects on the health of the host. These beneficial health effects are due to a selective stimulation of the growth and/or biological activity of a limited number of microbial genera, species, or strains in the gut microbiota that confer health benefits to the host, in particular the bifidobacteria and the lactic acid bacteria of the gut flora. Prebiotics have been shown to increase fecal and mucosal bifidobacteria in healthy subjects. Oligosaccharides are widely used in foods such as soft drinks, cookies, cereals, candies, and dairy products. Other applications for oligosaccharides such as an anti-cariogenic agent or a low sweetness humectant have also been explored.
The effects of prebiotics are principally due to selective stimulation of the growth of bifidobacteria (also known as a bifidogenic effect) and/or other beneficial bacteria in the gut. The stimulation of this growth allows a reduction in the pH of the colon, an increase in the production of short chain fatty acids, a prevention of the proliferation and adhesion of pathogenic microorganisms (barrier effect), an increase in the metabolization of potentially carcinogenic aminated compounds, and the production of vitamin B. A disadvantage of oligosaccharides nevertheless is that if they increase carbohydrate fermentation, they also increase gas formation. This means that the main side effects are flatulence, discomfort, and bloating.
Currently, the most clearly defined prebiotics are carbohydrates classed among dietary fibers: non-digestible oligosaccharides (also called oligosides). Oligosaccharides have a low degree of polymerization. The saccharide units involved in the formation of oligosaccharides are varied. Examples include hexoses, such as glucose, galactose, and fructose, and pentoses, such as xylose. Oligosaccharides may comprise a single type of monosaccharide (homo-oligosides) or a mixture (hetero-oligosides). Oligosaccharides are currently produced from the breakdown of natural polymers such as starch or inulin, from direct extractions out of natural substances, such as soybean, or from chemical or enzymatic syntheses.
The effects of specific prebiotics on many types of health problems are unknown. In the context of an unbalanced diet, broad sections of the population display an elevated content of blood fat values, in particular blood cholesterol values. High cholesterol levels are considered principal risk factors for cardiovascular disorders. Therefore, therapeutic treatments for significantly increased cholesterol values, in particular LDL cholesterol, and increased blood fat values, are urgently necessary. Various approaches to a solution have been described for this; however, the effects of specific prebiotic oligosaccharides on such cholesterol-related diseases or problems are not known. The effects of specific prebiotics on visceral pain and obesity (e.g., fat metabolism), which are problems that also have significant effects on broad sections of the population, are also unknown.